Bi-fold doors are commonly used as doors for closets or storage areas where a person opens a door for access to an area in only one direction.
Typically, a bi-fold door comprises four panels or doors in two sets. One advantage of bi-fold door pairs is that they may cover an opening of up to sixty to seventy two inches in which case each door panel measures essentially one quarter of the total opening. This permits the opening of the doors to a closet or storage area where, when fully opened both pairs of doors will only extend essentially one quarter of the distance of the opening into the room or hall from where the doors are opened. Typically, where four doors are used they are arranged in pairs where the doors of each pair are hinged to each other so as to fold outwardly from the opening. The outer door of a pair is pivotally connected at its top and bottom and a channel guide or track is provided on the upper horizontal member of the door frame or jam. The inner door of a pair has a bushing or roller attached thereto and extending upwardly therefrom adjacent the free end thereof which moves in the upper guide channel. The inner door of a pair is supported from the outer door. In some cases, where a smaller opening is provided only one pair of bi-fold doors may be utilized. Hand grips or handles are provided adjacent the hinged edges of the inner doors of a pair for gripping by a person and upon pulling by the person will outwardly fold each set of bi-fold doors to expose the closet or storage area.
The general purpose of the closet door or a door to other storage area may be considered to be to prevent accumulation of air born dust on clothing or other stored articles as well as to inhibit the entrance of insects such as moths thereto. These purposes also must be considered subservient to aesthetically covering a storage area and separating such storage area from the general part of a room such as a bedroom or an entrance hall.
Bi-fold doors do require manipulation by hand of each pair of doors and often the user must use two hands to effect closing of both pairs of a bi-fold door where two pairs are involved. Additionally, it is generally desirable to have the doors completely closed and remained in a completely closed position when access to the storage area is not desired. It is considered by some to be a nuisance to close both sets of bi-fold doors.
These problems with bi-fold doors as to closure thereof and maintaining in a closed position have been addressed in U.S. Pat. Nos. 3,181,596; 3,437,125; 3,116,782; but all of these patents disclose rather relatively complex mechanisms to achieve a very simple function. For example, U.S. Pat. No. 3,116,782 discloses a spring arrangement connected between a bi-fold door pair at hinged edges and requires routing of depressions for brackets for holding the springs. U.S. Pat. No. 3,181,596 requires a lever connected to the inner unit of a bi-fold door sliding on the upper support track and connected to a bi-fold door. U.S. Pat. No. 437,125 discloses a bi-fold door closer which is mounted within the door and comprises a pneumatically operated cylinder device which produces a restoring force on a cable which is attached to the innermost door.
As discussed these prior art closures and holders for bi-fold doors are rather complex and in some cases may be more expensive that the bi-fold doors themselves.
Accordingly, the present invention provides a new, novel and unique device for aiding in the closing and holding closed of bi-fold doors which is very simple in operation and requires very few parts.
An object of this invention is to provide a new and improved closing mechanism for a bi-fold door.
Another object of this invention is to provide a new and improved closing mechanism door which is easy to install and which lends itself to simple adjustment.